1. Field of the Invention
The invention relates to an electrical linear drive device comprising an outer housing, in which the drive part of a drive unit designed in the form of an electrodynamic linear direct drive is inserted axially like a cartridge so that an output drive rod of the drive unit protrudes from the front side of the outer housing, and the drive part has an external drive housing that accommodates a stationary drive coil arrangement and an axially movable armature, which is connected with the output drive rod and has a drive magnet arrangement, a position detecting means for the detection of at least one axial position of the movable unit comprising the armature and the output drive rod, and a central electrical interface means, connected both with the drive coil arrangement and also with the position detecting means, for external electrical communication.
2. Brief Description of the Related Art
An electrical linear drive device disclosed in the European patent publication EP 1047881, of this type includes an outer housing into which the drive part of a drive unit in the form of an electrodynamic linear direct drive is inserted from the rear side. The drive unit as such is capable of functioning, the outer housing providing inter alia the mechanical interfaces for external attachment. In the interior of the housing termed the drive housing of the linear direct drive there is a drive coil arrangement able to be supplied with an excitation voltage in a clocked manner and furthermore a permanent magnet drive arrangement able to be linearly shifted in relation to it and arranged on an armature, away from which a drive rod extends, which renders possible output of the kinetic energy to the outside. For detection of at least one axial position of the moving unit and comprising the armature and the drive rod the linear direct drive is provided with a position detecting means. A central electrical interface means, arranged on the rear of the drive housing, renders possible the supply of the actuating energy necessary to produce the linear movement and the output of the detection signals generated by the position detecting means. This rear arrangement of the central electrical interface means often interferes with the installation of the linear drive device at the site of installation. Furthermore the drive part at the end is more or less exposed in the output housing and may readily attract dirt or be subject to other kinds of mechanical disorders.
The German patent publication DE 10244261, B4, describes an electrodynamic linear direct drive, which is suitable for use in principle with the above mentioned linear drive device. Accommodation in an additional output housing is however not explicitly provided.
The European patent publication EP 0985831, A2, describes in conjunction with a fluid power linear drive the accommodation of an electrical interface means, serving for the output of detection signals on a side wall of the housing tube. In the interior of the wall of the housing tube of the linear drive a tube channel in which a printed circuit board is placed, which is on the one hand connected with the electrical interface means and on the other hand with is accommodated in the same tube channel. The fluid power linear drive is in this case like the linear direct drive of the said German patent publication DE 10244261, B4, a self-contained drive, which is not in addition placed in an additional output housing.